What is mapping?

Mapping is the process of representing the surface of the earth, objects on it, and the relative positions of the objects, to a suitable scale. In mapping, a large area of land is measured, surveyed, and plotted. The details of the objects present in the nearby surrounding area are located using conventional signs. All these processes are carried out on a flat paper known as a map.

History of mapping

The world’s first map is reported to be created by an ancient Greek philosopher Anaximander in the 6^th Century B.C. The main content of the map was major landmasses, namely Europe, Asia, and Libya, and four water bodies, namely the Mediterranean Sea, Nile River, Black Sea, and Phasis River. All these bodies were shown surrounded by the ocean on the map.

300 years later, the father of geography, Eratosthenes did an analysis of the known world and used mapping experiences of Anaximander and calculated the circumference of the Earth, created a map consisting of the longitudes and latitudes, and found the earth’s tilt. Eratosthenes’ map was the most advanced map in that era and its main content had around 600 cities.

Later, many cartographers analyzed previous maps and presented their versions of the world map, but the most specific map was created by Arno Peters with the help of James Gall who had good mapping experiences. Its map projection showed that the map was approximately correct to the present map. Later, the most accurate world map was created by Google in the year 2005.

Types of maps

It is important to learn various types of maps to use them for various purposes. The various types of maps are-

• Topographical map
• Cadastral map
• Engineering map
• Military map
• Geological map
• Archaeological map

Topographical map

The topographical map represents all the geographical, natural, and man-made features in the form of contours. Contours are the lines joining various points of the same elevation on a map. A topographical map shows details such as terrains, landforms, rivers, lakes, villages, hills of a region, and so on. Generally, topographical map is drawn to a scale of 1cm = 2.5km to 1cm = 0.25km.

Topographical maps are useful for engineers to plan roads, buildings, and any other structure. The maps help geologists to learn the type of rocks present in a particular region.

For mapping a topographical map, the geographical features are added to the map of the region concerning the points plotted and using the standard sign conventions.

Cadastral map

The cadastral map represents the boundaries of fields, houses, real estate, and other properties. The cadastral maps are generally drawn to the scale of 1:1,000, 1:2,000, 1:5,000, and 1:25,000.

Cadastral maps are useful for determining the legal estate boundaries of a person to prevent any dispute and to carry out any type of construction work on the property.

For mapping a cadastral map, a detailed cadastral survey is carried out. In this survey, the documents, sketches, diagrams, and plans are prepared and validated to ensure the proper boundaries of the estate. After the validation, the diagrams of boundaries are plotted on paper using a proper scale and a map.

Engineering map

The engineering map represents the details of engineering works such as roads, railways, tunnels, bridges, irrigation canals, reservoirs, and so on.

The engineering maps are the most important for the travelers to know the routes and for engineers for purpose of further expansion. For mapping, an engineering map, all the roads, railways, and other engineering features are surveyed to measure the distances, width, points of connection, and other specifications of the features, and diagrams are plotted to a proper scale on the map of the region.

Military map

The military map represents the railway and road communication with different parts of different countries. It also represents the rail and road connections to various strategic points useful for the defense of a country. The military maps are useful for the defense personnel and people related to the defense services of a country for the safety of the country.

Geological map

A geological map represents the various geological features of a region. It represents the surface strata, rock units, bedding planes, faults, folds, strike, dip, soil type, and so on. The geological map also represents the underground resources like minerals, oil, gravel deposits, and so on. To represent various features on a single map, different colors and symbols are used.

Geological maps help geologists to learn the rock and soil types, which is also useful in determining the availability of underground resources. It is also useful for geotechnical engineers to determine the soil type for determining the properties of soil.

Archaeological map

An archaeological map represents the places where ancient objects exist. It represents the ancient fossils, civilizations, structures, monuments, and so on.

The archaeological maps help archaeologists, historians, and researchers to learn information about the past of the region. It is also used by tourists to visit various historical places in the region.

General mapping process

For mapping, the first detailed survey of a region is done. During the survey, first, marking of various points in the region to be mapped is done. Mandatorily, points are accurately plotted on the outer boundaries of a region to plot regional boundaries perfectly. Next, using appropriate instruments, the bearing angles, elevations, depression, and distance between two successive points are measured and the readings are noted down in the field book. Next, using a proper scale, the points are plotted on plain paper to create the contours and the map.

Surveying process for mapping

The surveying broadly includes three processes, calculating chainages, calculating elevations depressions, and calculating the bearing angles.

• For chainage purposes, various points are marked in the region and on the outer boundary of the region using pegs. Distances between points are measured using chains and tapes. Next, the ranging is done.
• For calculating elevations and depressions, previously leveling instruments like dumpy levels, reversible levels, and tilting levels were used. Similarly, for calculating bearing angles, compass and cross staffs were used. Each successive point was beard using cross-staff and compass and then leveled using a dumpy level or any other leveling instrument.
• With the development in the field, various advanced instruments were developed. In present days, instruments like Theodolite, Electronic Distance Measurer (EDM), Total Station, and so on are used for both bearing and leveling.

Geographical Information System (GIS)

Geographical information system, computer software that gives information about any discipline. GIS captures, stores, manipulates, analyses, and displays spatial data and provides certain outputs requested by the users. GIS is widely used in surveying and mapping by engineers.

Global Positioning System (GPS)

The global positioning system is a technology used to locate an accurate location in a very short period. The GPS comprises three components, satellites, ground control stations, and user receivers. GPS is widely used for navigation purposes. GPS provides navigation to marine, air, and road vehicles. The GPS coordinates of any location can be obtained using Javascript, just the user needs to enable GPS on the device. A user can enable GPS on many electronic devices like mobiles, computers, and so on. GPS is also widely used for surveying and mapping. The GPS coordinates obtained in Javascript are used for preparing maps. Advanced technology has helped in creating various interactive maps. Interactive maps help to visualize maps easily. As it becomes easy to visualize, it becomes easy to understand. During the COVID-19 pandemic, GPS has helped lots of engineers to carry out works without physically visiting sites and getting affected by the COVID-19 virus.

Context and Applications

The mapping is useful for the students undergoing the following courses:

• Bachelors in Technology (Civil Engineering)
• Masters of Science in Building Surveying
• Postgraduate Diploma in Science – Surveying

Practice Problems

1. Who is credited for creating the world’s first map?

1. Ptolemy
2. Anaximander
3. Galileo
4. Eratosthenes

Answer- b

Explanation- Anaximander is credited for creating the world’s first map. As per the reports, the world’s first map was created by an ancient Greek philosopher Anaximander in the 6^th Century B.C.

2. Who is known as the father of geography?

1. Ptolemy
2. Anaximander
3. Galileo
4. Eratosthenes

Answer- d

Explanation- Eratosthenes is known as the father of geography. Eratosthenes was a mathematician, geographer, poet, musician, and astronomer. He is credited for calculating the circumference of the earth, and the earth's axial tilt. He was also the first person to create the projections of the earth including the latitudes and longitude.

3. Which mapping is done to locate faults and folds?

1. Topographic mapping
2. Geological mapping
3. Chromosome mapping
4. Archaeological mapping

Answer- b

Explanation- Geological mapping is done to locate faults and folds. Geographical mapping is used to represent the various geological features of a region. Various colors and symbols are used to represent the various geological features. The geological maps are created under the supervision of geologists who record the geological information about the field to be mapped.

4. Which mapping is done to locate boundaries of real estate?

1. Cadastral mapping
2. Geological mapping
3. Chromosome mapping
4. Spatial mapping

Answer- a

Explanation- Cadastral mapping is done to locate the boundaries of real estate. The cadastral map represents the boundaries of fields, houses, real estate, and other properties, which are prepared using the cadastral survey.

5. Which of the following is a technology used to locate an accurate location in a very short period?

1. GIS
2. Surveying
3. GPS
4. Map projection

Answer- c

Explanation- GPS is a technology used to locate an accurate location in a very short period. The GPS was first used by the United States Department of Defence in 1973. Currently, the GPS is operated by the US Space force.